• Title/Summary/Keyword: R&D Lab.

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A Study on the Application of Medical Compression Arm Sleeves Using a MRT(Moisture Responded Transformable) Fibers (MRT(Moisture Responded Transformable)섬유의 의료용 압박소매 적용에 관한 연구)

  • Cho, Daehyun;Jung, Taedu;Park, Eunhee;Park, Youngmi
    • Textile Coloration and Finishing
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    • v.33 no.2
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    • pp.87-95
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    • 2021
  • In this study, the application of a medical compression sleeve of Moisture Responded Transformable(MRT) fibers to the treatment of lymphedema after surgery in breast cancer patients was investigated. MRT fibers were manufactured with PET and Nylon6 bi-component cross-section yarns, and compression sleeves of sleeves 1, 2, 3, and 4 were knitted in order of size, and then the physical properties and clinical tests were evaluated. As a result, the pressure of compression sleeve in wrinkle was the lowest in sleeve 1 with 3.81 kPa, and the highest in sleeve 4 with 5.22 kPa. Elastic recovery rate is that all parts except the top of the sleeve 1 exhibited 100%. The air permeability was good at 12.1 ~ 16.1 cm3/cm2/sec, and peeling was also comparatively excellent as grade 3. In addition, the weight of the compression sleeves 1, 2, and 3 decreased as 18.3 ~ 23.0 g/m2 depend on size, while the compared sample was heavier with 17.39 ~ 32.61 g/m2. In lymphoscintigraphy test, it was confirmed that the function of remaining lymph node was good in all patients. Although there were no differences between samples in skin irritation and tightness in wearing comfort, the manufactured sleeves showed better fit, lightness, fashion and breathability than the comparable sleeves.

Development of Power Supply for Millimeter-wave Tracking Radars (밀리미터파 추적 레이더용 전원공급기 개발)

  • Lee, Dongju;Choi, Jinkyu;Joo, Ji-Han;Kwon, Jun-Beom;Byun, Young-Jin
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.21 no.4
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    • pp.123-127
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    • 2021
  • Millimeter-wave tracking radars should be operated in various environmental restrictions, thus they demand more computing power and smaller size compared to conventional tracking radars. This paper presents the design and implementation of the compact power supply for millimeter-wave tracking radar applications. To meet requirements of low voltage/high current and voltage accuracy for FPGA/DSP digital circuits, Point of Load (POL) converters are used in order to enhance power density and system efficiency. LDO (Low Dropout) is applied for the output voltage under the light load condition, then the single-input-multi-output power supply with max power of 375 W and 8 outputs is developed. The proposed power supply achieves output voltage accuracy of ±2 % and noise level of <50 mVpp % under full load conditions.

Electromagnetic Susceptibilty design of High-Speed Image Signal Processing Unit for Small Infrared Image Homing sensor (적외선 영상 호밍센서 고속 영상신호처리기의 전자기파 내성 설계)

  • Kim, Hong-Rak;Park, Jin-Ho;Kim, Kyoung-Il;Jeon, Hyo-won;Shin, Jung-Sub
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.22 no.2
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    • pp.27-33
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    • 2022
  • The small infrared image homing sensor is the eye of a guided weapon that has an infrared image sensor that identifies a target on the ground through day and night infrared image processing and searches, detects, and tracks the target. Inside the guided weapon since the power supply and communication line are used together with various components, the part against electromagnetic wave interference is very important. In particular, the effect of CE (Conducted Emission) through the power and communication lines connected by cables is very important. Through this method, it is possible to directly affect other components of the guided weapon. In this paper, the EMI filter and cable design for avoiding electromagnetic interference to the power input through the cable and the communication line are described. Also, the designed EMI filter is manufactured After the CE102 test of MIL-STD-461G, design satisfaction will be explained.

Effect of Surface Environment on Front Squat of Crossfit Athletes (지면환경이 크로스핏 선수의 프론트 스쿼트에 미치는 영향)

  • Jang, Yootae;Yoon, Sukhoon
    • Korean Journal of Applied Biomechanics
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    • v.32 no.2
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    • pp.49-55
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    • 2022
  • Objective: This study aims to verify the front squat motions using by two different surfaces, thereby elucidating the grounds for effective training environment that can minimize the risk of injury. Method: Total of 10 healthy male crossfit athletes were recruited for this study (age: 32.30 ± 3.05 yrs., height: 173.70 ± 5.12 cm, body mass: 82.40 ± 6.31 kg, 1RM: 160 ± 13.80 kg). All participants are those who know how to do front squats well with more than five years of crossfit athlete experience. All participants have sufficient experience in front squats on two types of surface which are soft surface (SS) and hard surface (HS). In each surface, participant perform 10reps of the front squat with 80% of the pre-measured 1RM. A 3-dimensional motion analysis with 8 infrared cameras and 2 channels of EMG was performed in this study. Paired sample t-test was used for statistical verification between two surfaces. The significant level was set at α=.05. Results: The significantly decreased rectus femoris muscle activation was found in SS compared with that of HS on phase 1 (p<.05). Also, ROM of ankle joint was significantly increased in the SS compare with that of HS on phase 1 (p<.05). The muscle activity ratio of gluteus maximus/rectus femoris showed a significant difference only in SS compared with that of HS on phase 1 (p<.05). Conclusion: In conclusion, Korean crossfit boxes should consider the use of hard surface, which has a relatively less risk of injury than soft surface, in selecting flooring materials. For the Crossfit athletes, they are also considered appropriate to train on a relatively hard surface.

Radiator Design Method considering Wide-Angle Beam Steering Characteristics of AESA Radar (AESA 레이더 광각 빔조향 특성을 고려한 복사소자 설계 기법)

  • Kim, Young-Wan;Chae, Hee-Duck;An, Se-Hwan;Joo, Ji-Han
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.22 no.5
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    • pp.87-92
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    • 2022
  • In this paper, a study was conducted on the design of an array element that can be applied to the AESA radar for seeker. An antenna for application to AESA radar should choose an optimal radiation element to be applied to an array antenna in order to secure electronical beam steering characteristics, and consider beam steering characteristics when designing. In particular, in order to satisfy the wide-angle beam steering characteristics, the wide-angle impedance matching technique should be used to minimize the scan blindness region that may occur during wide-angle steering. As such, securing the stability of system operation is becoming an important design consideration for AESA radar. In this paper, WAIM is applied to the end of the radiation element to improve the characteristics of the radiation element applied to the AESA radar antenna device, and the change in the performance of the active reflection coefficient, which is a stable operation index of the system, is reviewed. The final performance result verified the validity of the proposed method by mathematically synthesizing the simulation data.

Development of Power Supply for Small Anti-air Tracking Radar (소형 대공 추적레이다용 전원공급기 개발)

  • Kim, Hongrak;Kim, Younjin;Lee, Wonyoung;Woo, Seonkeol;Kim, Gwanghee
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.22 no.4
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    • pp.119-125
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    • 2022
  • The power supply for the anti-aircraft radar homing sensor should allow the system to receive power quickly and stably without the influence of noise. For this purpose, DC-DC converters are widely used for reliable power conversion. Also, switching of DC-DC converters Frequency noise should not cause false alarms and ghosts that may affect the detection and tracking performance of the system, and it should have a check function that can monitor power in real time while the homing sensor is operating. In order to apply to anti-aircraft radar homing sensor, we developed a multi-output switching power supply with maximum output 𐩒𐩒𐩒 W, efficiency 80% or more (@100% load), output power by receiving 28VDC input, and power supply to achieve more than 80% efficiency. A DC-DC converter was applied to this large output, and the multi-output flyback method was applied to the rest of the low-power output.

Standardized Extract (HemoHIM) Ameliorated High Intensity Exercise Induced Fatigue in Mice

  • Lee, Hyun Jun;Kim, Sang Back;Boo, Kyung Jun;Ortiz, Darlene Mae;Sayson, Leandro Val;Custodio, Raly James Perez;Cheong, Jae Hoon;Kim, Seul Ki;Kim, Mikyung;Kim, Hee Jin
    • Natural Product Sciences
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    • v.28 no.2
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    • pp.68-74
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    • 2022
  • HemoHIM was used as a Korean traditional medicine for anti-inflammatory and antioxidant effects. However, there is no study on the effect of HemoHIM on fatigue. We examined the potential use of HemoHIM to determine whether it can induce anti-fatigue effects. Mice were administered with HemoHIM and VEH for 14 days. On the last day of treatment, mice were subjected to behavioral tests. Subsequently, their plasma and muscle were collected after the treadmill test to measure lactate, lactate dehydrogenase (LDH), ammonia, corticosterone, glycogen, and creatine kinase (CK). We found that HemoHIM moderately increased the running time (s) in the treadmill and mobility duration in the cold swimming tests. In addition, the VEH group showed a significant increase in lactate, LDH, and corticosterone levels in the plasma compared to the group that did not perform the test. However, this was moderately reduced in HemoHIM treatment. Moreover, the HemoHIM-treated group showed significant differences in LDH and glycogen levels, and showed significantly different CK levels in the muscle. HemoHIM is considered to be effective in improving fatigue, given the duration of cold swimming or running time on a treadmill. Also, HemoHIM treatment resulted in reduced concentrations of blood and muscle parameter analysis.

Electromagnetic Susceptibility Design of Tracking Radar Systems (추적 레이다 시스템의 전자기파 내성 설계)

  • Hong-Rak Kim;Youn-Jin Kim;Seong-Ho Park;Man Hee LEE;Da-Been LEE
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.23 no.2
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    • pp.51-59
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    • 2023
  • The tracking radar system is installed and operated on the ground, ships, and aircraft, and requires a design to withstand electromagnetic interference with nearby electronic devices. In this case, radiation and immunity standards for cable connection must be satisfied to prevent malfunction of other equipment due to electromagnetic wave interference caused by cables connected to the tracking radar. The radiation standard must also be satisfied so that the electromagnetic wave noise generated and radiated from the tracking radar does not affect the peripheral device, so that the immunity standard for the electromagnetic wave emitted from the peripheral device must be satisfied. In this paper, we propose a design to satisfy MIL-STD-461G including CE, CS, RE, and RS, and explain design satisfaction through tests.

Development of Comprehensive performance test equipment to confirm the performance of small radar systems (소형 추적 레이다 시스템 성능확인을 위한 종합성능시험 장비 개발)

  • Hong-Rak Kim;Youn-Jin Kim;Seong-Ho Park;Man Hee LEE;Da-Been LEE
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.23 no.2
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    • pp.139-147
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    • 2023
  • The compact tracking radar system is a pulsed radar tracking system that searches, detects, and tracks targets in real time against aircraft targets with a small RCS(Radar Cross Section) maneuvering at high speed. This paper describes the development of comprehensive performance test equipment to verify the performance of the radar system in a anechoic chamber environment. Describes the design and manufacture of comprehensive performance test equipment to meet requirements, including the generation of simulated target signals to simulate aircraft target signals to verify performance in the laboratory environment of radar systems. It also describes a GUI(Graphic User Interface) program to check performance through a test in conjunction with the tracking radar system. Verify the comprehensive performance test equipment implemented through the performance test.

Measurement and Analysis of Physical Environmental Load during Handling and Distribution of Domestic Fruits -Focused on Seongju Korean Melon

  • Jongmin Park;Donghyun Kim;Wontae Seo;Hyunmo Jung
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.29 no.2
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    • pp.129-138
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    • 2023
  • The proportion of agricultural products handled through the Agricultural Products Processing Center (APC) is also steadily increasing every year, and in the case of Seongju Korean melon, a total of 10 APCs of Nonghyup and farming association corporations are in operation, and the distribution ratio is about 60% based on total production. In this study, Seongju Korean melon was selected as a target to analyze the environment load during carrying (production farm ~ APC) in the production area and the transport environment load during distribution of domestic fruits, and to analyze the environmental load for handling at APC. The vertical average vibration intensity (overall Grms of 1~250 Hz) of truck transport measured at three transport routes from Seongju Korean melon producer ~ APC, Seongju ~ Seoul and Seongju ~ Jeju was about three times larger than that in the lateral direction and 4.5 times larger than that in the longitudinal direction, respectively. The frequency of occurrence of high-amplitude events (G) in the vertical direction compared to the measuring time was deeply related to pavement conditions in the order of unpaved farm-roads, concretepaved farm-roads, and asphalt-paved main-roads, but overall Grms for the entire frequency band is believed to have a greater impact on vehicle traveling speed than road conditions. On the other hand, the difference in the size and direction of the vibration intensity measured by the forklift truck's main-body and the attachment (fork carrier) during handling at Seongju Korean melon APC was clear, and the vibration intensity of the forklift truck's main-body was largely affected by the stiffness of the fork and the mast according to the handling weight. Based on the field-data of the transport environment during domestic distribution measured through this study, it is believed that it is possible to develop a lab-based simulation protocol for appropriate packaging design.